稻細蟎防治藥劑及適期之研究

Abstract

1.室內藥劑殺瞞效果試驗，未選出良好藥劑，但藥劑加入乳化劑證明可增加殺蟎效果。較顯著者如Azodrin+Sapogenat T180及MIPC+Phenylsulfanat CA. 2.從田間藥劑適期防治知，乙基巴拉松及安殺番均具相同藥效，唯兩者殺蟎效果均欠佳。防治適期以插秧後30天至60天（即分蘗盛期～齊穗前）為宜，約10天噴一次。但此項觀察仍待選出有效藥劑經田間試驗才能確證。 3.稻細蟎有經由秧苗被帶至本田的可能，一般潛伏於葉耳及葉舌處，初期徵為葉鞘上端有褐斑，因此今後田間調查應儘早注意，以防患於未然。 4.幾年來田間調查顯示，在二期稻作初期若逢高溫乾旱，則細蟎很難在孕穗期建立高密度而造成其後嚴重為害，該作大發生可能性即小，因此田間調查密切監視其活動，是不可忽略的事。 1. Twenty-four pesticides were tested in the laboratory. No chemicals showed high efficacy. However, effectiveness was much improved when certain emulsifiers were added to pesticides, e. g. Azodrin+Sapogenat T 180 and MIPC+pheiylsulfanat CA. 2. Field trials showed that the effectiveness of both ethyl-parathion and endosulfan was about the same, both showing poor control of the rice mite. The proper timing for chemical control should initiate at the active tillering stage till heading and space at no more than 10-day intervals. 3. The rice tarsonemid mite could be found at earlier stages of rice seedling. This might be overlooked by field researchers before because of small samples. 4. Field surveys data seem to bear the conclusion that high temperature and drought conditions during June and July will drastically reduce the probability of an outbreak of this mite. 5. The author would like to suggest that pesticide toxicologists watch for the resistance of the mite to chemicals and improve pesticide formulation for field trials. Whenever possible, field screening of pesticides be conducted to continuously search for effective chemicals. Close in-season field surveillance for earlier detection of the mite’s appearance be made routinely by local extension workers with special attention to the seedling stages before and after transplanting during the second crop.